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Arc Fault Breaker Install - Does it matter which White wire?

Arc Fault Breaker Install - Does it matter which White wire?

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  #1  
Old 06-13-18, 07:38 AM
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Arc Fault Breaker Install - Does it matter which White wire?

Replacing current breaker with an= Arc Fault breaker in my Square D box.

I can take the current black wire and put into new Arc Fault breaker.

The white pigtail wire goes to the neutral bar.

However, I need to take an existing white wire from neutral bar and connect to the new Arc Fault. How do I know which one is correct? Does it matter?

See pic. Thank you
 
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  #2  
Old 06-13-18, 08:29 AM
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Yes, it matters.

Follow the black wire into the cable assembly and use that white one.
 
  #3  
Old 06-13-18, 08:43 AM
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Well, I wonít be able to do that. But, couldnít I just use porocess of elimination by disconnecting a white wire one at a time from neutral bar until I figure out which one it belongs to?
 
  #4  
Old 06-13-18, 09:28 AM
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My first question would be why is there a white and black wirenutted together in the panel?
 
  #5  
Old 06-13-18, 09:34 AM
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I would hesitate using trial and error. The neutrals are current-carrying, so unless you power down the whole panel while you're working, there's a definite shock hazard.

I can just about see where the black wire goes in the picture. Why can't you trace it to the top of the panel?

The other option would be to turn off the main breaker and use a meter as a continuity checker, disconnect the neutrals that it may be, and figure out using the meter.

The GFI portion of the CAFI breaker works by checking the outgoing current vs the incoming current, which is why both hot and neutral is required.
 
  #6  
Old 06-13-18, 09:36 AM
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Why can't you do that? Doesn't the black come from a jacketed cable(Romex)?
 
  #7  
Old 06-13-18, 12:49 PM
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It would make sense to follow the black back to the entry into the panel and look for the white in the same sheath.
 
  #8  
Old 06-13-18, 01:58 PM
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I followed the black wire to where the entry point where it enters the box, and there are a few different colored wired that are coming through that bunch. A green, maroon, white, etc. I just tried to disconnect the white from neutral bar, and the breaker still works. I tried the green as well, and still works.

Could the white wire be fed from another entry point in the box? There are six entry points along the top of the box.
 
  #9  
Old 06-13-18, 04:13 PM
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What do you mean that the breaker still works? The circuit is still hot with the breaker on testing it at an outlet on that circuit (hot to neutral has current) ?
 
  #10  
Old 06-13-18, 10:24 PM
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@ 1madmouse..... that splice appears to be supplying neutral to a transformer.

I just tried to disconnect the white from neutral bar, and the breaker still works.
Sure..... the breaker is getting hot off the bus and neutral thru the tail but the circuit won't operate properly. There is no way around it...... you need to identify the exact white wire that is associated with that black wire. You mentioned maroon. If that's a red wire..... you won't be able to use an arc fault breaker on that circuit as the neutral is used by two circuits..... red and black.
 
  #11  
Old 06-13-18, 10:47 PM
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The whole idea of arc faults is to detect faults in a given circuit. Using a white connection to common bus exposes it to other circuits and compromises the whole idea. Find the white wire coming from the same sheaft as the black.

Arc faults provide very valuable protection, especially with older wiring. I put them on all the original circuits in my 60 year old home.
 
  #12  
Old 06-14-18, 05:54 AM
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Is the walol above the panel finished? It looks like it isn't or if it is you can carefully cut a small hole and check that way. May need to loosen the cable and see what moves when you push or wiggle the hot wire.
 
  #13  
Old 06-15-18, 08:36 AM
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I realize that, but you never use a black for the neutral, too confusing. At least that is how I was taught, no splices in the panel, and always color match for clarity. You guys are right on making sure you use the same neutral as the hot comes from. Thank you PJmax
 
  #14  
Old 06-15-18, 08:47 AM
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So i got this hooked up correctly now. However, after a night of it working, I woke up this AM and the breaker has tripped. I flipped it back to "on" and is working now. Is that any sort of red flag?
 
  #15  
Old 06-15-18, 09:24 AM
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Yes it is red flag. Either the arc fault breaker is defective or there is a fault on the circuit. The simplest test is to replace it with another arc fault. It it does not trip after a few days it was probably the first breaker.

If it does trip the second breaker you have an issue with that circuit. Check all the connections on that circuit. Switches and receptacles may have built up a carbon film that is the trigger. Most difficult is finding a defect in the cable.

Look on the national data on residential fires that were caused by electrical wiring as reason to deal effectively with this issue.

https://www.nfpa.org/News-and-Resear...ics/Electrical
 

Last edited by doughess; 06-15-18 at 10:43 AM.
  #16  
Old 06-15-18, 09:52 AM
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thanks and I'll try another breaker. even if i kept the current breaker and just lived with it tripping, the fire risk would be gone, correct?
 
  #17  
Old 06-15-18, 02:27 PM
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If the breaker keeps tripping the issue needs to be found and corrected .
 
  #18  
Old 06-15-18, 07:46 PM
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ARMINIUS: ....... even if i kept the current breaker and just lived with it tripping, the fire risk would be gone, correct?
WRONG Not Correct: The risk is in that circuit, not the breaker. Arc are very bad things, they start fires. Just think of there being a smoldering arc or fire someplace in the house.

Ignorance may be bliss but this is dangerous!
 
  #19  
Old 06-17-18, 04:24 PM
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So to figure out where the issue is causing the breaker to trip, is it depending on when the switch or outlet is engaged? Iím trying to figure this out as the breaker doesnít trip right away, but I normally notice it the next day.
 
  #20  
Old 06-17-18, 10:16 PM
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You don't figure out where the arc is. You look for it, or eliminate that part of circuit as cause.

It may be in a section of wire, switch or receptacle. When that item is removed from circuit, breaker no longer trips. So you replace it.
 
  #21  
Old 06-18-18, 07:38 PM
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I would be willing to bet it is something that comes on at night like a freezer or refrigerator compressor, something that pulls some amps when it starts. But never just live with it, could be slowly smoldering inside the wall. You want to find and correct the problem. I think it makes some of us here nervous just to know you have that going on.
 
  #22  
Old 06-19-18, 02:24 PM
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So I'm working one receptacle and switch at a time. If my receptacle test shows "correct", would that be one I could assume is not causing the issue?

Also, if a light if wiring incorrectly, but the switch is not engaged, could I rule that out as the issue?
 
  #23  
Old 06-19-18, 08:00 PM
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Sounds like you are using a GFIC Receptacle tester. In most situations they do not detect arcs. They simply measure and check that the current flow in each wire is equal... if not they pop.

https://www.homedepot.com/p/Klein-To...T210/206517824

Approach this as process of elimination. Find a box midway in the circuit. Disconnect the wiring to the farthest from the breaker panel. If over night the breaker pops it in the wiring before your disconnect . If it did not pop then the issue is in the disconnect section. Keep narrowing it down.
 
  #24  
Old 06-24-18, 04:57 AM
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Wanted to let everyone know I figured out the issue. I did not have an arc coming from any receptecles or lights. The issue was a shared neutral between two circuits in my breaker box. This was comman back in the day. So per the inspector, I pigtailed those hots together in the box and everything works great with no arcs!
 
  #25  
Old 06-24-18, 06:24 AM
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Single pole AFCI devices cannot be used on a multiwire circuit. However, many manufactures are now making two pole AFCI breakers for use on multiwire circuits.
 
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